Technical Field
The embodiments herein generally relate to power generation and specifically to power optimization of a power generator.
Description of the Related Art
Solar photovoltaic (PV) panels are becoming an increasingly popular means of generating electrical power. PV panels are comprised of individual solar cells connected in series. The open circuit voltage of a PV panel depends on the number of cells in the panel. Solar cells based on silicon technology typically have an open circuit voltage of about 0.7 V. A PV panel with 60 serially connected cells would have an open circuit DC voltage of around 42 V. Solar cells within a PV panel are often organized into sub-strings. A 60 cell PV panel is often organized as three substrings of 20 cells each. Contact points to connect to the sub-strings are often available inside a panel. PV panel currents are typically at least several amperes. PV panels are often serially connected together to form “strings” to increase the output voltage of the PV panel array and reduce wiring losses. It is common to have as many as 20 PV panels in a string producing an open circuit string voltage on the order of 1,000 V.
The DC current of a PV panel is variable and depends on it operating voltage as well as a variety of other parameters including the amount of insolation it receives, its age, any shadowing and soiling. Physically identical PV panels can therefore have different currents. A problem of serially connecting PV panels is that the PV panel with the lowest DC current will limit the current of the entire string and reduce the amount of useful power the string can produce.